In applications where parts are required to be manufactured to a high level of precision, for example in the airline and aerospace industries, highly accurate quality control mechanisms must be in place in order to ensure that parts are manufactured to specification without divergence from the design or error. Whilst highly accurate manufacturing machines are used to manufacture parts in these industries, errors may still be present in a particular part.
It is impractical and indeed impossible to visually inspect many of these parts by eye and obtain any degree of confidence that the part has been manufactured exactly to specification.
Video measurement machines are used to inspect manufactured parts. These machines generally have an image capture device, such as a digital camera or the like, and data processing and storage capabilities. The part is placed within the field of view of the image capture device and the design technical specification of a manufactured object, referred to in the art as the parts program, is stored within the storage device of the measuring machine.
The parts program includes a series of features associated with the manufactured object. Each feature in the parts program has a series of attributes associated therewith including the feature's geometric properties and spatial location on the object and illumination, magnification and focus settings to allow the measurement machine to capture a suitable image of the feature.
When the parts program is executed, instructions are provided to the operating program of the measurement machine to control the camera and move the camera relative to the object in order to measure each of the features of the object recorded in the parts program. Typically, measurement machine operating programs move through the features recorded in the parts program sequentially and capture the features on the object independently to determine whether the object has been manufactured in accordance with the design specification without error.
For objects that are large and/or have a large number of physical features requiring inspection and measurement, this process can be time consuming. As the measurement and inspection process is part of the manufacturing process, any reduction in the time required to perform this highly accurate quality assurance will deliver reductions in manufacturing time and hence a benefit to the manufacturer.
In this specification, the terms “comprises”, “comprising”, “includes”, “including” or similar terms are intended to mean a non-exclusive inclusion, such that a method, system or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.